title: Stress reactions to cognitively demanding tasks and open-plan office noise.
abstract: OBJECTIVE
  To investigate the effects of cognitively demanding work tasks and office noise on heart rate variability (HRV), cardiovascular responses and electromyography (EMG) activity in the trapezius muscles.
  
  
  METHODS
  Ten female volunteers were exposed to simulated open-plan office noise for 35 min (Leq 65 dBA), while engaged in cognitively demanding tasks. Task performance, self-rated stress and energy, affective state, perceived exertion in the shoulders and in the head, EMG in the left and right trapezius muscle, blood pressure, heart period length, HRV, and salivary cortisol were measured.
  
  
  RESULTS
  Cognitively demanding work tasks were associated with changes in HRV, systolic blood pressure and EMG that reflects increased sympathetic activity in the autonomic nervous system. No effect of noise was observed, except for a higher rating of perceived exertion in the head and, contrary to expectations, a 4% lower diastolic blood pressure in the noise conditions.
  
  
  CONCLUSIONS
  Psychophysiological measures reflected the mental load imposed by cognitive work tasks. Short-term exposure to office noise resulted in increased ratings of perceived exertion in the head, but not in physiological stress reactions.
authors.affiliation: National Research Centre for the Working Environment, Lersø Parkalle 105, 2100, Copenhagen, Denmark. jkr@nrcwe.dk
authors.forename: Jesper
authors.initials: J
authors.lastname: Kristiansen
authors.forename: Line
authors.initials: L
authors.lastname: Mathiesen
authors.forename: Pernille Kofoed
authors.initials: PK
authors.lastname: Nielsen
authors.forename: Ase Marie
authors.initials: AM
authors.lastname: Hansen
authors.forename: Hitomi
authors.initials: H
authors.lastname: Shibuya
authors.forename: Helga Munch
authors.initials: HM
authors.lastname: Petersen
authors.forename: Søren Peter
authors.initials: SP
authors.lastname: Lund
authors.forename: Jørgen
authors.initials: J
authors.lastname: Skotte
authors.forename: Marie Birk
authors.initials: MB
authors.lastname: Jørgensen
authors.forename: Karen
authors.initials: K
authors.lastname: Søgaard
mesh_terms: D000328:Adult; D000342:Affective Symptoms / Q000503:physiopathology / Q000523:psychology; D001794:Blood Pressure / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D004576:Electromyography; D005260:Female; D006321:Heart / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000503:physiopathology; D009623:Noise, Occupational / Q000009:adverse effects*; D005082:Physical Exertion / Q000502:physiology; D012463:Saliva / Q000737:chemistry; D013315:Stress, Psychological / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D013647:Task Performance and Analysis
chemical_list: D006854:Hydrocortisone